Performance analysis of pulse position based chirp spread spectrum technique for multiple access

The paper presents a new wireless communication system using Chirp Spread Spectrum (CSS) transmission. The applied modulation scheme is extended with Pulse Position Modulation (PPM) to transmit data for multiple mobile terminals simultaneously. The proposed system is a Low-Power Wide-Area Network (LPWAN) providing very reliable and robust transmission, especially for terminals moving with high speeds or at long range, but has limited throughput. These features makes it a perfect candidate for such communication environments, where transmitting control or other critical information is necessary. The extensive analytical investigations are also presented regarding to the instantaneous and average symbol-error rate (SER) in Rayleigh fading channel. The numerical results show that the Pulse Position based Chirp Spread Spectrum for Multiple Access (PP-CSS-MA) technique is able to provide higher data rates comparing to the original CSS transmission, while only a slight increase of SNR is requied to achieve the same Symbol-Error Rate (SER). Furthermore, the average transmission power barely increases when applying higher data rates of PP-CSS-MA.